8 replies to this topic

[fjhdavid]

Hello,

 

I did my first DSO picture, M13 with an LS6 + antares reducer 6.3 + APN Eos T2i  (one CCD pixel = 1.1 arcsec)

 

12 frames of 60s exposure time but I kept only 5 of them

 

Image processing: DeepSkyStacker + Iris (Lucy Richardson deconvolution filter)

 

Francois

Attached Files

•  M13 LS6.bmp   3MB   218 downloads

[MistrBadgr]

Thanks, Francois, for sharing!  Nice image of M-13, which is always fascinating.

 

I look forward to see more of your exploits!

 

Best Regards,

 

BIll Steen

[Bob Arnold]

Francois,

Nice image. Is there much light pollution where you live?  I noticed that your tracking looks very good. Does the software you use utilize star registration?

Bob Arnold 

[fjhdavid]

I was on holidays with a clear sky (I would say, after picture measurement, that the background level is around mag 19.5 / 20)

 

I use "Iris" software from C. Buil, which is a free astro software which implement the "Lucy Richardson" deconvolution filter. This filter is used with the Hubble telescope. The only drawback is the consuming time (around 10mn for a 1024x1024 pixels frame). But the results are incredible.

 

Francois

 

PS: I tested several exposure time from 15s to 240s (with a step of 15s between each image); 60s is the best option, but you will have to leave about 60% of "bad quality frames" before stacking them. But, "DeepSkyStacker" will do the selection automatically for you and it is a free software!

[gfamily]

Is that cropped? - I've got a wider image without a focal reducer with my dSLR. 

As per 

 

[fjhdavid]

yes it is crop to 1024x1024 around the image center, in order to reduce the processing time.

 

your picture looks great!!

 

could you, please, tell me your exposure time and number of stacking frames?

 

and load a.bmp picture?

 

thanks

[gfamily]

Hi - they were 20 second exposures at ISO 3200. 

 

I stacked 6 images for that one - but I think I need a tutorial in DSS to be able to get a better image. 

[fjhdavid]

DSS is very powerful and the defaults settings are very good.

 

I just choose the "RGB channel alignment" and the cosmetic pixels removal (1pixel and 50%). The two background calibration are good! anyway, you will have to do a color balance, at the end, in order to choose the final "look" that you prefer

 

After that, when the frames registration is finished (thanks to the "score" parameter), I always have a look to the FWHM of the best frames and I always check visually the best frames I plan to keep.

 

and that's all, at least for me!

 

François

 

ps: Don't forget to remove the offset frames! (dark removal for APN is not necessary, at least for short exposure time)

[Betty L Myers]

I say thanks s too..

They are very nice pics. I have the LS 8" and a Novas' at this and hope to be able to take pics as good as yours some day.  I am learning from you and I thank you very much for the info..